<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .bgc {
      color: red;
    }
  </style>
</head>

<body>
  <div id="test"></div>

  <script src="./js/react.development.js"></script>
  <script src="./js/react-dom.development.js"></script>
  <script src="./js/babel.min.js"></script>
  <script type="text/babel">
    const arr = ['a', 'b', 'c']

    const VDOM = (
      <div>
        <ul>
          {
            arr.map((item, index) => {
              return <li key={index} className={index % 2 == 0 ? 'bgc' : undefined}>{item}</li>
            })
          }
        </ul>
      </div>
    )

    ReactDOM.render(VDOM, document.getElementById('test'))
  </script>

</body>

</html>